Servo operation, with or without simulated bounce is also possible as well as installing working lights where feasible.
There are also options for jig-built laddering etc and additional detail.
A few notes on construction:
Tubular posts are made from brass tube
Square Posts are usually either made from square brass, suitably tapered or etched brass.
Lattice posts from etched brass
Operating wires from Nickel Silver wire, thickness depends on scale.
Other Signal Parts:
4mm scale either Alan Gibson Workshop, MSE or Scalelink
7mm scale either MSE or Scale Signal Supply
2mm, 4mm and 7mm GWR finials Modelu 3D printed finials with hollow ball.
2 and 3mm scales MSE
Working Lamps - I use warm white SMD LEDs, the smallest I can easily get - they fit in all lamp castings for 7mm and 4mm scale. Each LED has its own 1K resistor and separate wires. I do not use the post etc for return. They can be wired into the servo leads if required.
Servo Boards from GF Controls, Megapoints (and MERG if you are a member). Each have their strengths and weaknesses.
Gantries can also be supplied but costs vary depending on scale and specification.